A dual camera system uses a single lens and no moving parts in the optical path. A single lens directs a desired scene to a partially reflective beamsplitting mirror, thence to a pair of image sensors. For day/night operation, one sensor may be optimized for nighttime sensitivity, while the other is...http://www.google.de/patents/US7768566?utm_source=gb-gplus-sharePatent US7768566 - Dual-mode camera
